T' followin' excerpt is from "Extreme Rocketry". The intention is t' allow guests t' get a basic feelin' about a kit. Avast, me proud beauty! We strongly suggest that you get a copy o' t' referenced Extreme Rocketry and read the entire article. Inside you will find many helpful hints in construction as well as other useful information. Ahoy! For more information, use t' link above.

• "One o' t' favorite rockets in me collection has a classic 54mm Slimline Motor Retainer installed. It is reliable and easy t' use, matey, but I had always thought t' design would be slightly better if it used some kind of threaded retention."
• "It's as if someone read me mind, because Slimline Motor Retainers now come in a threaded version, in sizes from 29mm t' 98mm."
• "There are other really good threaded retainer systems available but these units have an external closure ring."
• "... Ahoy! t' external design creates more drag, ...."
• "T' threaded Slimline is comprised o' three components:"
• "A base, a threaded ring, and an extraction tool (not completely necessary, but makes life simpler)."
• "T' base glues t' your motor tube (you'll need about 1/2" of motor tube stickin' out."
• "Then insert your motor and secure with t' ring. Begad! That's it."
• "I recommend a nice loot savin' option if you plan t' outfit more than one rocket; buy t' "starter set" for your first rocket, me bucko, then buy only a base for each additional rocket."

T' Slimline Retainer has been around for quite some time. Based on this review it sounds like t' product has just gotten better. Blimey! Ahoy! T' only con listed was that thar are cheaper retainer systems available if you don't need a minimum diameter system.