.top{margin-bottom:30px;}.top li{margin-left:5%;margin-right:5%;margin-top:10px;line-height:120%;list-style-position:outside;}Wolf Tooth Axle Trainer Caps Silver. Trainer Caps allow thru-axle bikes to be used with most wind magnetic or fluid cycling trainers. Cold weather and short days are never far from a Minnesotans mind so Wolf Tooth engineers created Trainer Caps to reduce barriers to winter workouts. Non-drive side axle caps are joined by drive-side plugs that can be installed or removed without tools to make the prospect of hopping on the trainer a little more bearable.Compatibility: Wolf Tooth Rear Axles (not compatible with rear axles from other manufacturers) Plug has O-ring retention C;o; no tool required