Good device which looks like it would be difficult to overcome.

I bought this after the review on Bike Social. It's a seriously good piece of kit, especially when used in conjunction with the Protector chain. It's an ideal size for under-seat storage, or slipping into a bag/pocket. It feels really sturdy and well made and is a great price. The communication from David was first-class - I got the impression that he really cares about customers. I highly recommend buying from this company.

I've had one of these for years, it's been used and abused and hasn't missed a beat. Still looks like new too! I needed another lock and it was an easy choice to get the same again. Fit and finish is excellent and from my experience above, so is the durability.

These guys take security very seriously, know their products and are willing to advise to make sure the customer gets best option for the application/s .... my order has included Noose Chains, Round Locks & Dib Locks all keyed alike ... SFB have been happy to split orders to get what I needed and the quality of the items received are top notch! .... any trustworthy security is going to represent a high outlay but compared to what else is on the market I have what I need and can trust at a fair price and delivered quickly too ...Thank you SFB!

I am very pleased with the roundlock. I only use it as a disc lock, added my own ‘Remove before Flight’ warning safety pin and it is great. I can sleep a bit better at night now
I was previously using an Oxford Omega disc lock, but these are ridiculously easy to break after checking-out some YouTube videos.
If I could improve it, I’d make the black plastic on it dayglo or red colour to be more noticeable as a disc lock.
Service was good, ordered it late on Monday and got it Wednesday.

I just got it. It feels really solid and well built.
It was delivered to dublin in few days.

An ingeniou slittle lock. Small and mighty! I'm super happy with this working alongside my accompanying 22mm Titan Chain for 'motorbike at home' security. Used with the Sub Major Ground Anchor, a high quality alarmed disk lock and a security camera on 24/7, I'm covering all the bases to avoid my bike dissapearing at least without evidence or a whole heap of noise and disruption. I truly cannot see anyone bothering to try! Pragmasis comms, timing, service and superb qaulity of items is exceptional. Thank you.

Researched videos from Bennetts. Great lock for the Protector chain and doubles as a portable disc lock.

Great product and excellent communication with David throughout the purchase/shipping process - highly recommend

Came on time and it was up to expectations. Great service!

Just got my second one of these having been impressed by it’s top performance in Bennett’s bike social lock testing. It’s clearly bombproof as well as being compact, not so heavy and can be used as both a disc lock and as a super tough padlock on suitable chains (I use it with the adapter to fit the 19mm chain I have at home). At this price why wouldn’t you get one?

In search of an excellent high safety system for securing my bike I found Pragmasis. I am very lucky because it seems there is nothing comparable in whole Austria.
The double doofer ground anchor together with the massive 19mm protector chain and the SS65CS-XLN padlock is a really highest-level protection system. And I think as long as there are so many other bikes less or not additional secured at all, the thieves will choose those bikes instead of mine.
The ground anchor came perfectly packed together with the entire fixing kit. After I fixed it to the concrete floor, I pulled one end of the heavy 19mm chain through. Then I put a SFB RoundLock RL21A through this end link, to make it impossible to pull it back. The RoundLock together combined with the 19mm chain end link is too big to pass the double doofer anchor. Therefore, I have the whole length of the chain available, and don’t need the chain in double length (the chain is really heavy!). On the other end I use the Anti-Pinch Pin together with the SS65CS-XLN padlock to lock the bike.
PERFECT SOLUTION, thanks to Pragmasis for the ideas, the implementation and the highest quality!
Customer service by David Briggs is excellent and very friendly!
Absolutely recommended company!
Best regards, Wolfgang, Vienna

Bought it due to all the positive "theft attack" reviews which it has. Received it yesterday and it seems really solid and well made. Works perfectly. Hopefully it´ll last me for long. Recommend 100%.

Great Quality,i bought RL21 plus RL21A.
Very happy.Thank you

After a theft of high end bikes from my garage, I researched on the internet and came across this company, the range of products is excellent, a one stop shop for bicycle security. First class products and first class customer service . The round lock is a brilliant invention. Highly recommendable

Great quality lock chosen after a lot of research. Using as a disc lock on some planned trips and will be using it with a Pragmasis chain and groundanchor that I will be ordering in the near future for home security.

I've two now and they are an excellent compact unit which fits the 16mm links perfectly. Great reviews from the security experts. Excellent value for money.

My MT07 was recently stolen so upgrading security for my next bike. This has consistently been recommended as one of the best disc locks you can buy - I’ll be investing in their chains too. You’ll have to Houdini to steal my freaking bike!

Got this to go with a 14mm Pragmasis chain I bought a few years ago.
Fits very well through link with only small gap.
Centre pin is very thick so don't think it would be quick to cut with a disc cutter. I expect anyone would therefore go for the chain.
I had my doubts about its use as a disk lock but it does work on my bike with cast wheels - goes between the cast centre and the disc. It may not work for all types.
The lock itself is very smooth and easy to use.
Overall I'm very pleased especially at the price - you can't buy a better lock for that money.
Pragmasis were as usual very quick and efficient.

The disk lock is heavy duty and fits the disc perfect. For the price it’s a bargain Oh and fast delivery as well.

Excellent service

Perfect, hard to use bolt cutters on it not easy to pick in public i expect, just check it will fit your disc first or it makes an excellent lock for a chain.Fast delivery.

A good product backed by honourable people.

Love the compactness of this lock, especially given the level of security it offers! Works really well with a 16mm chain. Highly recommend.

A good quality lock, which is easy to transport on a bike as a disc lock.

I now have two of these, one of which is used with the Pragmasis 16mm chain (also excellent). It's really a nicely designed and engineered bit of kit with its lovely chrome finish and compact dimensions.
Ordering and delivery from securityforbikes.com was hassle free and very fast. Very satisfied all round.

On one hand, i never want a thief trying to steal my bike. On the other hand, i would love to see a confused thief eyeing up this lock.

Great lock at a great price.
Service also great - Ordered and delivered within 48hrs.
Would definitely recommend this company.

I want to secure my bike when out and about so will pair this with the excellent protector noose chain. This is an extremely well thought out product which should keep my property safe and is lighter than the Squire CS 65 I use at home

After seeing a Bennetts Insurance Youtube video where they were rated very highly by the real world tester I ordered two of these with matching keys. That gives me six keys, any one of which will open the locks, so I can carry a couple of spares with me and still have some at home. The locks themselves are excellent quality and feel pretty heavy duty. I am very pleased with my purchase.

I dont find any probem using my roundlock at all.....have you tried taking off your gloves?