speed bag

Robert B.Parkerの小説、私としては3冊目の "Valediction" を読むことにしました。

Henry Cimoli had a full range of Nautilus equipment installed at the Harbor Health Club. The whole place was getting out of hand. There were women in there now as well as men. There was a lounge where you could sit around in a velour sweat suit and drink carrot juice, there had been complaints that the speed bag in the boxing room made too much noise, and some of the people working on the Nautilus wore Lacoste shirts.

私が通っているフィットネスジムも最近フィットネス用のボクシングを教える様になって、そのクラスがある時は音が煩くて、なるべく離れた場所にあるランニングマシンを使うようにしています。
そのボクシングクラスで使っているのはシリンダー状のサンドバッグあるいは "punching bag" ですが、上の引用文に出てきた "speed bag" はそれとは別物でしょうか？　辞書を見ます。

・Oxford English Dictionary: A small punching bag used by boxers for practicing quick punches.: 'Practice the jab on the heavy bag, focus pads, shadow boxing, double end bag and for advanced boxer's the speed bag.’

・Wikipedia: （抜粋）Speed bags are small, air-filled bags anchored at the top to a rebound platform parallel to the ground. Speed bags help a fighter learn to keep his or her hands up, improve hand-eye coordination, and learn to shift weight between feet when punching.

そうか、"speed bag" の本物は見たことがありませんが、TVのドラマで見たことがあります。